Celebrity couple Ashton Kutcher and Mila Kunis, both former stars of "That 70s Show," among other television and film credits, visited Rock City and Ruby Falls on Monday. The couple reportedly was traveling from Florida, where they had attended her brother's wedding, to Nashville.

While at Rock City, they met "gnome doctor" Matthew Dutton in the Fairyland Caverns. Kutcher gave a shout out to Dutton on his Twitter account, thanking him for "keeping Rock City magical for future generations."

An employee alerted Rock City President Susan Harris that the couple was there.

"I saw them taking a selfie at Lover's Leap, and I said, 'Hey, I'd be happy to take a photo for you' and he handed me his phone and they showed me what they wanted," Harris said.

Harris mentioned that though the weather didn't make for a "Chamber of Commerce" type of day, it did keep the crowd down.

"He, I think it was, said, 'It's not often we get a chance to do something like this without being bothered.'"

The couple went to Ruby Falls, too.

Micah Jones was the tour guide for the couple and a family of four. He said bad puns about rocks are part of his shtick and that Kutcher added a few of his own.

"He enjoyed them and helped contribute," Jones said.

The pair also had lots of questions about the cave and its history and took a few seconds to take advantage of their surroundings once inside the Waterfall Room.

"They did a nice little ballroom dance in there while the music was playing. It was kind of majestic."